Electron-discharge device



Nov. 10,192 1,560,690

. W, G. HOUSKEEPER ELECTRON DISCHARGE DEVICE Filed April' 21, 1923 I whunmg JIIIIM! a 1 l g |l|| W Patented Nov. 10, 1925.

UNITED STATES. PATENT. OFF-ICE.

WILLIAM G. HOUSKEEPER, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRICCOMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION 015 NEW YORK.

ELECTRON-DISCHARGE DEVICE.

Application filed April 21, 1923. Serial No. 633,654.

'1 '0 all whom it may concern Be it known that I, WVILLTAM G. Hous-KEEPER, a citizen of United States, residing at New York, in the countyof New York, State of New York, have invented certain new and usefulImprovements in Electron- Discharge Devices, of which the following is afull, clear, concise, and exact description.

This invention relates to electron discharge devices and moreparticularly to such devices of the external anode type.

The object of this invention is to unite a metaland a vitreous materialto form a vacuum tight seal.

This object is attained by fusing the vitreous material to the metal insuch a manner that the edge of the metal is completely out of contactwith the surface of the vitreous material. A seal of this characterjoining together materials having different coefficients of expansionmaintains its tightness up to the fusing temperature of either of itscomponents.

Referring now to the drawing, the singlefigure discloses an electrondischarge device constructedin accordance with the invention.

The enclosing vessel of the electron discharge device comprises asubstantially cupshaped portion 10 of vitreous material and a metalliccupshaped portion 11 which are joined together at their open ends byfusion or welding. The joining together of the two portions 10 and 11 ispreferably accomplished by inserting the open end of the portion 11 wellwithin the open end of the poi-- tion 10, heating the rim of the portion11 to soften it and compressing it against the surface of the portion 11to fuse it thereto. The operation of compressing the vitreous materialagainst the surface of the member '11 is accomplished in such amannerthat the rim of the member 11 is completely out of contact with thesurface of the member 10. The seal is made in this manner so that noportion of the rim of the member 11 can be embedded in any of thematerial of the member 10, for, with materials having differentcoefficients of expansion, if any appreciable amount of the metallicmember is embedded in the vitreous member, the seal will fail or crackupon the change of temperature. As is clearly shown in the drawing, therim of theportion 11 extends a substantial distance into the interior ofthe portion 10 and is out of contact therewith. It is, of course,apparent that the vitreous material may be fused to the interior of theportion 11 rather than to its exterior surface as is shown in thedrawing. In either event, however, the rim of the metal portion 11 ismaintained completely out of contact with the vitreous material.

The metallic cup-shaped portion is preferably composed of copper and ispreferably of less thickness adjacent its edge where the vitreous.material, preferably glass, is fused thereto. There is a considerabledifference between the coefficients of expansion of these materials, butwith the type of seal above disclosed, a vacuum tight union ismaintained between the members 10 and 11 up to the temperature of fusionof the glass. The glass portion 10 is provided with a re-entrant stem 12from which are supported a grid 13 and a cathode 14, the metal portionllserving as the anode of the de vice. The supporting structure for thegrid and cathode is not disclosed in detail but may be of the typedisclosed in my copending application Serial No. 578,292, filed July 29,1922.

The invention claimed is: -An electron discharge device comprising ametallic cup-shaped anode, a cup-shaped glass member joined to saidmetallic mem ber to form therewith a vacuum tight enclosing vessel, saidglass member-having a portion fused to the exterior of said anode at apoint removed from its edge, the diameter of said glass member beingvincreased adjacent the edge of said anode whereby said edge is out ofcontact with said glass member, and an electrode supported by said glassmember. I

In witness whereof, I hereunto subscribe my name this 19th day of AprilA. D. 1923.

WILLIAM G. HOUSKEEPE-R.

